Detachable junction between the ends of two suction cleaner tubes



A. G. R. VON DEN BAUMEN 2,973,972 DETACHABLE JUNCTION BETWEEN THE ENDS OF Two SUCTION CLEANER TUBES Filed Aug. 19, 1957 March 7, 1961 AI'INVENTOR I m,Dwm.M,

ATTORNEYS United States Patent DETACHABLE JUNCTION BETWEEN THE ENDS OF TWO SUCTION CLEANER TUBES Arnold George Rolf von den Baumeu, Wassenaar, Netherlands, assignor to Holland-Electro C.V., Rotterdam, Netherlands, a Dutch limited partnership Filed Aug. 19, 1957, Ser. No. 678,972

Claims priority, application Netherlands Aug. 23, 1956 4 Claims. (Cl. 285-"7) The invention relates. to detachable junction between the ends of two suction cleaner tubes, the end in question of one tube being adapted to telescope into the corresponding end of the other tube. Such a junction is generally known and herein the end of one tube forms a sliding fit with the end of the other tube. It has been found that after prolonged use, during which the tube ends have frequently been moved in and out, one or both of the tube ends is (are) deformed or some rust is formed; in consequence of which the tubes cannot be detached any more or will get undone during use.

The invention has for its object to'provide a tube junction of the above type in which this drawback has i been removed.

According to the invention this object is attained by the fact that at the place of the overlapping of the tubes there has been applied a ring of flexible material, preferably of a polyamide, provided with inwardly directed cams, which extend through openings positioned in a circle round the end of the outer tube. In telescoping the two tube ends, the end of the inner tube is engaged by the circle of cams, each of which is slightly shifted in the radial direction while the tube end is pushed in, which is possible because the ring is of flexible material. In this way the ring itself is prestressed so that it engages the end of the inner tube with stress.

In a preferred embodiment the cams are flexible material, and the cams and openings are positioned in two parallel planes perpendicularly to the longitudinal axis of the tube, the cams in the two planes being so shifted relative to each other that a cam in one plane covers the space between two adjacent cams in the other plane, while the distance between the two planes is so slight that a hermetical junction is obtained when the junction is in operating condition.

The detachable junction according to the invention presents the great advantage that with an equally effective junction the frictional resistance between the cams of the ring and the operative surface of the end of the inner tube is much smaller than the frictional resistance between the operative surfaces of the two tube ends in the known detachable junction. Further the tubes telescope smoothly into each other and the tubes will never get stuck owing to corrosion, as is usually the case with the known detachable junction. Finally the junction according to the invention has the advantage that it is not necessary to use tubes which fit each other accurately; the junction of tubes slightly diflering in diameter is also possible. Consequently in manufacturing it is not necessary to maintain narrow tolerances.

The claimed rights also extend to the ring, which can be used for either of the above mentioned embodiments. In the first mentioned embodiment the ring is characterized in that it is made of flexible material and is provided with inwardly directed cams, while in the preferred embodiment the ring is characterized in that the ring and the cams are of flexible material and the cams are positioned in two parallel circles lying in planes perpendicular ice 2 to the axis, and are shifted relative to each other in the two circles so that, in axial alignment, a cam of one circle covers the space between two adjacent cams in the other circle.

The invention is explained more in detail with reference to the drawing, which illustrates two embodiments.

Fig. l is'a longitudinal cross-section through the detachable junction according to the invention.

Fig. 2 is a longitudinal cross-section through this junctionalong the line 11-11 in Fig. 1. 1

Fig. 3 is a longitudinal cross-section of another embodiment of the detachable junction according to the invention.

Referring to Figs. 1 and 2 the two telescoping tube ends are designated by the reference numbers 1 and 2. The outer tube 1 is provided with a number of openings 3 positioned in a circle round this end. Fitted over said circle of openings there is arranged a ring 4 having inwardly directed cams 5, six of which have been shown in Fig. 2, but it will be obvious that the number of said openings may be chosen at will. As is clear from Fig. 2, these cams 5 extend through the openings 3 and rest against the operative surface of the end of the inner tube 2. The junction between the tube ends is effected by the clamping force with which the cams 5 engage the. inner tube. This clamping action is effective in case the circumferential length of the inner tube at this place is slightly greater than that of the hypothetic circle through the operative surfaces of the cams. This implies that in inserting the end of the inner tube the cams 5 have to yield slightly in the radial direction, In view thereof the ring 4' consists of flexible material, preferably of a polyamide, so that the ring body can yield in radial direction.

In order to make it possible for the inner tube to be inserted without abutting against the cams 5, the end of said tube has been formed slightly conical, as shown at 6 in Fig. l. .T-his involves that the outer tube 1 also must be slightly conical in this place, in order to prevent the possibility that during the use of the suction cleaner an air current of such intensity is produced between the two tubes in the overlapping zone that the operation of the suction cleaner is adversely affected by itf A hermetical junction between the two tube ends is obtained in the embodiment according to Fig. 3. Here the outer tube 1 is provided with two circles of openings, while the ring 4 is correspondingly provided with two rows of cams. The openings (and also the cams) in the two circles are so shifted relative to each other two adjacent openings in the other circle.

' bodiment the cams are of flexible material, just like the ring body. In inserting the inner tube a force in the radial direction is exercised on the cams, which in this case, because the cams themselves are of flexible material, results in the ends of the cams also expanding in the lateral direction. The relative distance between the two circles of openings (and cams) has been chosen so that owing to the expansion of the ends of the cams in the axial direction the cams of one circle come iuto contact with the cams of the other circle, so that a hermaterial circumposed on the outer tube and having cams of flexible material extending through the openings to,

bear against the inner tube, said cams and openings being Patented Mar. 7, 1961 positioned in two parallel planes perpendicularly to the longitudinal axis of the tubes, the cams and the two planes being so shifted circumferentially relative to each other that a cam in one plane covers the space between two adjacent cams in the other plane, and the distance between the two planes being so slight that in assembly each cam will be pressed outwardly and expanded in directions perpendicular to its axis whereby the circumferences of adjacent cams will touch each other so that a hermetical joint is obtained when the junction is in operative condition.

2. A detachable junction between the ends of an inner and outer suction cleaner. tube, the end of the inner tube being tapered to telescopically fit in the end of the outer tube, said outer tube having circumferentially spaced openings formed therein, a ring of flexible material circumposed on the outer tube and having cams of flexible material extending through the openings to bear against the inner tube, said cams being arranged in two parallel circles perpendicular to the axis and the cams being so shifted circumferentially relative to each other in the two circles that in axial alignment a cam in one circle covers the space between two adjacent cams in the other circle.

3. A pair of air tubes having a detachable connection between adjacent ends thereof, said tube ends being disposed in telescoped relation and including an inner tube end and an outer tube end, said tube ends being disposed in closely spaced apart relation to prevent substantial leakage of air therebetween, said outer tube end having a plurality of radial circumferentially spaced openings positioned generally in a circle and spaced from the extreme end of said outer tube, a continuous ring of flexible material encircling the exterior of said outer tube end in overlying relation to said openings and having inwardly projecting portions in the form .of cams extending through said openings and projecting slightly into the interior of said outer tube end, each of said cams being of no greater lateral extent than its respective opening to permit outward movement of said cams, said inner tube end compressively engaging said cams and thereby forming a friction interlock between said tube ends, said cams having a substantial axial extent to suitably support said inner tube, and the extreme end portion of said inner tube end being tapered to facilitate the positioning of said inner tube end within the general confines of said cams.

4. The connection of claim 3 wherein said outer tube end has a tapered intermediate portion on the side of tube said cams remote from the extreme end of said outer end, said inner tube end tapered portion and said outer tube end tapered portion being in engagement to provide additional support for said tube ends.

References Cited in the file of this patent UNITED STATES PATENTS 2,246,404 Ross June 17, 1941 2,396,491 Chamberlain Mar. 12, 1946 2,457,908 Meyerhoefer m Jan. 4, 1949 2,562,359 Iredell July 31, 1951 2,757,942 Eberhart Aug. 7, 1956 2,784,011 Roberts Mar. 5, 1957 2,829,909 Magnani Apr. 8, 1958 FOREIGN PATENTS 3,520 Great Britain Feb. 12, 1907 40,407 France Mar. 22, 1932 382,185 Great Britain Oct. 20, 1932 

